Tancredi Parmeggiani was born in Feltre in 1927. After spending his childhood in Belluno, in 1943 he interrupted classical studies to enroll in the artistic high school in Venice, which he completed two years later. In 1946 he enrolled at the Academy of Fine Arts in Venice to follow the courses of the Free School of the nude, taught by Armando Pizzinato. In this period he met and made friends with Emilio Vedova. At the end of 1947 the painter went to Paris, where he met the European avant-garde of the first half of the century. Between 1948 and 1949 he lived and worked between Feltre and Venice and, in May 1949, he held his first personal exhibition at the Galleria Sandri with a presentation by Virgilio Guidi.
In 1950 he stayed in Rome, where he joined the Age d'Or group, which organized exhibitions and publications dedicated to the international avant-garde. The following year he took part in the 1a Mostra dell'arte astratta italiana at the Galleria Nazionale d'Arte Moderna e Contemporanea in Rome. Shortly thereafter he returned to Venice, where he met Peggy Guggenheim, who provided him with a study of Ca’ Venier dei Leoni on the Grand Canal and introduced him to the world of international collecting. Approaching also the environment of the Galleria del Cavallino by Carlo Cardazzo, participating in the Premio Graziano in December 1951, Tancredi Parmeggiani, he would later join the Spatial Movement of Lucio Fontana, signing, among other things, in May 1952, the Manifesto del Movimento Spaziale per la Televisione. Between 1952 and 1953 Tancredi won the first prize in Venice from the Bevilacqua La Masa collective exhibition with the work Aspirazione a New York.
In 1953 he exhibited at the Galleria del Naviglio in Milan, presented in the catalog by Peggy Guggenheim; he was in the Italia-Francia exhibition in Turin, where his works were placed alongside those of Hans Hartung. In 1954 he participated in Tendances Actuelles with Pollock, Wols, Mathieu at the Kunsthalle Bern. 1955 began with the definitive separation from Peggy Guggenheim and ends with the departure for Paris, where he exhibited in a collective at the Galerie Stadler. In Paris he met Dubuffet, Asger Jorn, Karel Appel.
In the following years Tancredi Parmeggiani exhibited at the Saidenberg Gallery in New York, at the Hanover Gallery in London, at the Galleria Selecta in Rome and participated in Carnegie International in Pittsburgh. In 1958 he married the Norwegian painter Tove Dietrichson. Between 1958 and the end of 1959 he shared a study in Palazzo Carminati, home of the Bevilacqua la Masa Foundation.
In 1959 he exhibited at the Galleria dell’Ariete in Milan, with which he would begin an ongoing relationship; then for a few months he returned to Paris, where his daughter Elisabeth was born in December. In 1960 he travelled to Norway and exhibited at the Anti-Procès exhibition at the Galleria del Canale in Venice, joining the movement promoted by Alain Jouffroy and Jean Jacques Lebel against abstract academism. In 1962, after a trip to Sweden, he exhibited at the Venetian Galleria del Canale and the Galleria Levi in Milan, and also received the Marzotto Prize in Valdagno. In this period, after the cycle of the Facezie and the Diari paesani, Tancredi significantly named some of his Hiroshima paintings, also creating the series Fiori dipinti da me e da altri al 101% in manifest opposition against the commodification of art.
At the end of the same year a long nervous crisis began, which forced him to be hospitalized in a clinic in Monza. He staid briefly in Rome in 1963 and, shortly after the birth of his son Alessandro, he returned to Venice with his sister. Here he had a new hospitalization; he exhibited again in 1964 at the Venice Biennale and, after a short trip to Sweden with his wife, he returned again to Rome, a guest of his brother. Subsequently, he took accommodation in a small hotel in Campo de 'Fiori. Here, at the dawn of September 27, 1964, at the age of 37, Tancredi Parmeggiani took his own life, throwing himself into the Tiber. His corpse was found on October 1st.